North Korea today announced it had carried out its first nuclear
weapons test, sparking an immediate barrage of condemnation from
world leaders.

The test was the equivalent to blowing up 550 tons of TNT,
a state-run South Korean geological institute said.

"It amounts to detonating 550 tons of trinitrotoluene, or TNT,
at once,'' said Park Chang-soo, a spokesman of the Korea Institute
of Geoscience and Mineral Resources.

However, Russian Defence Minister Sergei Ivanov was quoted as
saying by ITAR-TASS news agency that the strength of North
Korea's nuclear test was five to 15 kilotons (of TNT),

"The power of the test that was carried out reached between five
and 15 kilotons,'' Ivanov said.

The White House today condemned North Korea's nuclear test
as a "provocative act'' and called for immediate action by the UN
Security Council.

No excessive radioactivity was detected in South Korea
after the test, experts said.

"No radioactivity has not yet been detected from the alleged
nuclear test,'' said Han Seung-Jae, director of the state-run
Nuclear Emergency Preparedness Departmen. "It might not be detected
at all if the alleged nuclear testing was conducted in a tightly
sealed atmosphere such as a deep tunnel, and all radioactive rays
and fallout are contained,'' he said.

North Korea's official Korean Central News Agency (KCNA)
said the underground test was carried out safely and successfully
and there was no radiation leak.

'Indigenous wisdom'

"The nuclear test was conducted with indigenous wisdom and
technology 100 per cent,'' KCNA said.

"It marks a historic event as it greatly encouraged and pleased
the KPA (Korean People's Army) and people that have wished to have
powerful self-reliant defence capability.''

"The nuclear test is a historic event that brought happiness to
our military and people,'' KCNA said.

"The nuclear test will contribute to maintaining peace and
stability in the Korean peninsula and surrounding region.''

World condemns test

The United States and China led global condemnation of North
Korea today after the reclusive state announced it had carried out
a nuclear test, slamming the move as a provocation and demanding a
tough UN response.

The 15-member Security Council was expected to hold an emergency
meeting on the North Korean test later today.

A UN spokeswoman said the Security Council had no immediate
comment on the news.

China, Pyongyang's closest ally in the region, expressed its
``resolute opposition'' to the ``brazen'' test.

"China strongly demands the DPRK (North Korea) side to undertake
its commitments to the non-nuclearisation of the Korean Peninsula,
and stop all actions that can lead to the deterioration of the
situation,'' the foreign ministry said in a statement on state
television.

China also urged North Korea to return to six-party talks aimed
at reining in Pyongyang's nuclear program.

In Washington, White House spokesman Tony Snow stopped short of
confirming that Pyongyang had tested a nuclear device but said a
seismic event had been recorded at a suspected nuclear test
site.

"A North Korean nuclear test would constitute a provocative act
in defiance of the will of the international community and of our
call to refrain from actions that would aggravate tensions in
Northeast Asia,'' Snow said.

"We expect the Security Council to take immediate actions to
respond to this unprovoked act.''

Snow said that aside from an emergency session of the Security
Council, the United States would hold talks with other participants
in the six-party talks with North Korea - China, Japan, Russia and
South Korea.

Japanese Prime Minister Shinzo Abe said that the test was
unpardonable but warned against a kneejerk reaction.

"North Korea's nuclear weapons test can never be pardonable. But
we should collect and analyse more intelligence on the matter in a
cool-headed manner,'' Abe said in Seoul, where he was to hold talks
with President Roh Moo-Hyun.

"Whatever provocation by North Korea should be dealt with a cool
head. Maintenance of bilateral relations (between Japan and South
Korea) is important,'' he said.

South Korea accused its northern neighbour of "trampling
on the international community's expectations for resolving the
nuclear issue peacefully'', and said it would not tolerate a
nuclear-armed North.

In Moscow, Russian President Vladimir Putin condemned the
nuclear weapons test, Russian news agencies reported, as Russia
demanded that North Korea rein in its nuclear program.

"Enormous damage has been done to the process of
nonproliferation of weapons of mass destruction in the world.''

In Europe, British Prime Minister Tony Blair condemned the test
as a "completely irresponsible act'', while Britain's Foreign
Office vowed the international community would ``respond
robustly''.

"This further act of defiance shows North Korea's disregard for
the concerns of its neighbours and the wider international
community,'' Blair said.

France said the test was ``a very grave act''.

"It is now up to the international community to react to this
new situation and to come up with a firm response to Pyongyang: we
will engage in consultations with other members of the United
Nations Security Council and the countries in the region without
delay,'' French Foreign Minister Philippe Douste-Blazy said.

German Foreign Minister Frank-Walter Steinmeier said that North
Korea had increased its ``self-imposed isolation'', also calling on
the Security Council to ``react firmly''.

The test had pushed the country ``further down the wrong path,
to self-imposed isolation,'' Steinmeier said.

The European Union called the reported test ``unacceptable'',
saying it ``profoundly jeopardises regional stability and
represents a severe threat to international peace and
security.''

Nuclear-armed India said it was ``deeply concerned'', while
Pakistan - the last country to test a nuclear weapon - said it
deplored the test, saying it was a destabilising development for
the region.

"It is regrettable that DPRK chose to ignore the advice by the
international community not to conduct the test,'' Pakistan's
foreign office said.

Howard 'disturbed and outraged'

Australia fears the Asia-Pacific region is more dangerous after
North Korea conducted its first nuclear weapons test.

The Government and Labor joined the world community in
condemning North Korea for conducting the test and called on the
United Nations to take decisive action.

Prime Minister John Howard warned the nuclear test will
destabilise the region and further isolate the Stalinist state.

"We are both disturbed and outraged at this action by North
Korea which should be condemned in the strongest possible terms,"
he told parliament.

"The test has destabilised the region, it's eroded North Korea's
own security."

Foreign Minister Alexander Downer described it as a "gloomy day"
for international affairs.

"If this test is confirmed - and we think it's likely to be -
then it's a very big setback, particularly to the security of North
Asia, which is what worries us," he told ABC Radio.

"We're after all an Asia-Pacific country ourselves."

Mr Downer has concerns about what it means for security in North
Asia, particularly its impact on Japan.

There are fears the test may prompt Japan to develop its own
atomic arsenal, heightening nuclear tensions in the region.

"It not only will cause a sense of outrage amongst the
leadership of North Asia but amongst the general public there,
particularly in Japan, but I'd also have to say I think in China
there will be enormous concern about this," he said.

"Ultimately the great worry is that these sorts of events can
lead to the proliferation of nuclear weapons."

Australia - one of the few countries with formal relations with
Pyongyang - plans to lodge an official protest once it has final
confirmation of the test.

Mr Downer may call in North Korea's ambassador Chon Jae Hong as
early as tomorrow morning to make Australia's anger known.

Australia wants the United Nations to take action under Chapter
Seven of its charter, which could pave the way for international
sanctions, possibly even military action.

For the moment, the Government has flagged it will seek targeted
financial and travel sanctions, trade and aviation
restrictions.

UN warning

The UN Security Council last Friday urged North Korea not to
carry out its planned test, warning Pyongyang of unspecified
consequences if it did.

North Korea announced last week it would test a nuclear device
saying its hand was forced by what it called US threats of nuclear
war and economic sanctions. But it said it would not be the first
to use a nuclear weapon.

Analysts say North Korea probably has enough fissile material to
make six to eight nuclear bombs but probably does not have the
technology to devise one small enough to mount on a missile.

The dollar rose to a seven-month high against the yen on reports
of the test, but analysts did not expect long-term fallout unless
the situation deteriorated further.

"The economy of North Korea is virtually closed from the rest of
the world and its regional impact won't be very significant unless
there was a major military confrontation,'' said Wang Qing, an
economist at Bank of America in Hong Kong.